Cool Bookshelves

Just a quick post today I'm afraid. I have been doing some serious homework all day and this is all I really have time for. Here is a link to some seriously cool bookshelves. I don't particularly approve of Number 10 and I don't really understand how Number 17 is working, but these are still some pretty cool bookshelves. Which one's your favorite? I like number 9, but I also think that number 18 is pretty cool. How has everyone's 2013 been so far?